Interleukin-1 (IL-1) type cytokines and their respective receptors have been studied with much interest over the past ten years. Additionally, other molecular entities which have effect on or in association with the IL-1 cytokines and receptors have also drawn much interest. One such molecule has been a protein receptor antagonist now termed Interleukin-1 receptor antagonist (IL-1ra).
IL-1B is known to be a cytokine that triggers inflammatory processes (Dinarello C A, Interleukin-1 and Interleukin-1 Antagonism. Blood 1991; 77: 1627-1652) The action of the receptor antagonist, IL-1ra, presently appears to generate its effect by competitively blocking the ligand (IL-1) for the receptor (Dinarello C A, Interleukin-1 and Interleukin-1 Receptor Antagonist. Nutrition 1995; 11: 492-494). Studies have indicated that IL-1ra may have important implications for use as a therapeutic agent in the treatment against inflammatory diseases including endotoxin-induced shock, pancreatitis, mastitis, and rheumatoid arthritis (Ohlsson K, Bjork P, Bergenfeldt M, Hageman R, and Thompson R, Interleukin-1 receptor antagonist reduces mortality from endotoxin shock. Nature 1990; 348: 550-552; U.S. Pat. No. 5,508,262 by Norman J G, Interleukin-1 receptor antagonist decreases severity of acute pancreatitis, 1996, University of South Florida, Tampa, Fla.: U.S.A.; Shuster D and Kehrli M, Administration of recombinant human interleukin 1 receptor antagonist during endotoxin-induced mastitis in cows. American Journal of Veterinary Research 1995; 56: 313-320; Evans C H and Robbins P D, Progress toward the Treatment of Arthritis by Gene Therapy. Annals of Medicine 1995; 27: 543-546). Such therapeutic administration has been contemplated using the protein or its antibody via several regimens including oral, intravenous, intraperitoneal, intranasal, and subcutaneous administration. Where arthritic conditions are contemplated, direct injection into the joints is contemplated to directly administer the protein to the disease site where the ligand appears to migrate and induce the inflammatory response of the arthritic condition. Intra-synovial expression of human IL-1ra in rabbits is protective against injection of human IL-1, however, use of human IL-1ra does not protect against rabbit IL-1 induced arthritis in rabbits (Hung G, Galea-Lauri J, Mueller G, Georgescu H, Larkin L, Suchanek M, Tindal M, Robbins P, and Evans C, Suppression of intra-articular responses to interleukin-1 by transfer of the interleukin-1 receptor antagonist gene to synovium. Gene Therapy 1994; 1: 64-69; Lewthwaite J, Blake S, Hardingham T, Warden P, and Henderson B, The effect of recombinant human interleukin 1 receptor antagonist on the induction phase of antigen induced arthritis in the rabbit. Journal of Rheumatology 1994; 21: 467-472). Human IL-1ra has been tried in bovine to reduce the inflammation of mammary gland (Shuster D and Kehrli M, Administration of recombinant human interleukin 1 receptor antagonist during endotoxin-induced mastitis in cows. American Journal of Veterinary Research 1995; 56: 313-320). However, although IL-1 bioactivity in milk was prevented, no effect of using human IL-1ra was shown in the bovine model. Moreover, human IL-1ra does not bind to bovine neutrophil IL-1 receptor (Lederer J and Czuprynski C, Characterization and identification of interleukin 1 receptors on bovine neutrophils. Journal of Leukocyte Biology 1992; 51: 586-590). Therefore, there is a direct indication in the art for a need to obtain species specific receptor antagonists for use against various disease states in which use of receptor antagonist is indicated to be useful in treatment of such disease states.
The IL-1ra gene sequence has been identified in several species. Protein and/or DNA sequence has been disclosed for, human, mouse, rabbit, and rat (Eisenberg S P, Evans R, Arend W, Verderber E, Brewer M, Hannum C, and Thompson R C, Primary structure and functional expression from complementary DNA of a human interleukin-1 receptor antagonist. Nature 1990; 343: 341-346; Carter D B, Deibel M R, Dunn C J, Tomich C-S, Laborde A L, Slightom J L, Berger A E, Bienkowski M J, Sun F F, McEwan R N, Harris K W, Yem A W, Waszak G A, Chosay J G, Sieu L C, Hardee M M, Zurcher-Neely H A, Reardon I M, Heinrikson R, Truesdell S, Shelly J, Eessalu T, Taylor B, and Tracey D, Purification, cloning, expression and biological characterization of an interleukin-1 receptor antagonist. Nature 1990; 344 : 633-638; Lennard A, Gorman P, Carrier M, Griffiths S, Scotney H, Sheer D, and Solari R, Cloning and Chromosome Mapping of the Human Interleukin-1 Receptor Antagonist Gene. Cytokine 1992; 4: 83-89; Matsushime H, Roussel M, Kouji M, Hishinuma A, and Sherr C, Cloning and Expression of Murine Interleukin-1 Receptor Antagonist in Macrophages Stimulated by Colony-Stimulating Factor 1. Blood 1991; 78 : 616-623; Zahedi K, Uhlar C, Rits M, Prada A, and Whitehead A, The mouse interleukin 1 receptor antagonist protein: Gene structure and regulation in vitro. Cytokine 1994; 6: 1-9; Goto F, Goto K, Miyata T, Ohkawara S, Takao T, Furukawa S, Maeda T, Iwanaga S, Shimonishi Y, and Yoshinaga M, Interleukin-1 receptor antagonist in inflammatory exudate cells of rabbits. Production, purification and determination of primary structure. Immunology 1992; 77 : 235-244; Cominelli F, Bortolami M, Pizarro T, Monsacchi L, Ferretti M, Brewer M, Eisenberg S; and Ng R, Rabbit Interleukin-1 Receptor Antagonist. J. of Biol. Chem. 1994; 269 : 6962-6971). The protein sequences of the known species are very similar as noted in FIG. 4. As shown the Table I, the highest percent homology is between rat and mouse at 90% and the lowest homology is between human and rat at 75%. In the table, D=dog, H=human, M=mouse, RB=rabbit, and R=rat.
TABLE I ______________________________________ R M H D RB ______________________________________ R 100 M 90 100 R 75 77 100 D 74 74 80 100 RB 78 79 78 76 100 ______________________________________
Thus, as indicated from the homologies, it is likely that species specific binding may be necessary for the canine IL-1ra protein to interact with its respective receptor molecule(s) to provide effective treatment for such clinical indications as IL-1 associated arthritis. As is typically the case concerning ligand, receptor, and a receptor antagonist binding, the variation in amino acid sequence is very important to the specific binding characteristics. Moreover, in a long-term treatment, small differences between the same protein in different species may give rise to an immune response. One objective of the current invention is to alleviate the likelihood of an immune response by obtaining canine IL-1ra to be used specifically in dog species.
In studying the effect of IL-1ra in treatment of various disease states, including arthritic conditions, canine species have been recognized as an appropriate animal model (Caron J F, Fernandes J C, Martel-Pelletier J, Tardif G, Mineau F, Geng C, Pelletier J P, Chondroprotective effect of intraarticular injections of interleukin-1 receptor antagonist in experimental osteoarthritis. Supression of collagenase-1 expression. Arthritis and Rheumatism 1996; 39: 1535-1544; Picvance E O, Oegema T R, Thompson R C, Immunolocalization of selected cytokines and proteases in canine articular cartilage after transarticular loading. Journal of Orthopaedic Research 1993; 11: 313-323; Fernandes J C, Caron J P, Martel-Pelletier J, Jonanovic D, Mineau F, Tardif G, Otterness I G, Pelletier J P, Effects of tenidap on the progression of osteoarthritic lesions in a canine experimental model. Suppression of metalloprotease and interleukin-1 activity, Arthritis and Rheumatism 1997; 40: 284-294). Moreover, many breeds of dog are susceptible to arthritic disease and can benefit directly from advances in the art to treat canine arthritic conditions. The current invention advances such art through obtaining canine IL-1ra DNA sequence from which the protein may be produced for use in treatment of canine diseases including arthritis.